Highlights of the American Diabetes Association 83rd Scientific Sessions
Authors: Flávia Oliveira Geraldes
Journal: The Lancet Healthy Longevity (2023)

The American Diabetes Association 83rd Scientific Sessions were held in San Diego, CA, USA (June 22–26, 2023) and featured a number of sessions on the care of diabetes in older adults. Guy Taylor (Newcastle University, UK) presented data from a qualitative study using the Capability, Opportunity, Motivation, and Behaviour model to investigate behaviours related to resistance exercise in mildly frail older adults (≥60 years) with type 1 (n=13) or type 2 (n=3) insulin-treated diabetes. The authors found that primary barriers to resistance training, which is associated with improvements in frailty and sarcopenia outcomes and with better blood glucose control, fell into the domains of capability, motivation, and opportunity. Most participants were unaware of the benefits of exercise on diabetes and muscle health and reported being told at diagnosis that exercise was unsafe for individuals with diabetes. Facilitators to resistance exercise included an informative and flexible training environment, clarity on diabetes-specific benefits of physical activity, and having a supportive partner, ideally also capable of exercise. The study suggests that older, mildly frail adults with insulin-treated diabetes are a vulnerable group whose perception of the disease can prevent them from engaging in regular physical activity, and who might benefit from tailored awareness programmes and flexible exercise environments. Doohwa Kim (Pusan National University Hospital, South Korea) presented data from a 10-year longitudinal validation analysis within the Korean Genome and Epidemiology Study, evaluating the contribution of worsening insulin resistance to disease progression in 3700 participants with normal baseline glucose tolerance, and identified metabolic characteristics of non-progressors and progressors to prediabetes or type 2 diabetes. The study found that progressors to prediabetes or type 2 diabetes had lower baseline β-cell function and higher baseline insulin resistance than non-progressors. Insulin sensitivity decreased faster (46·4% in progressors to type 2 diabetes vs 31·1% in progressors to prediabetes vs 16·6% in non-progressors), showing that worsening insulin resistance and lower β-cell function are key pathological factors in the development of type 2 diabetes in lean individuals, and suggesting that maintaining insulin sensitivity with lifestyle interventions might help to prevent diabetes in those with low β-cell function. Ildiko Lingvay (University of Texas Southwestern Medical Center, USA) presented data from the head-to-head, double-blind, 1:1 randomised, phase 3a ONWARDS 3 trial of insulin icodec, a once-weekly basal insulin analogue, versus once-daily insulin degludec in adults with insulin-naive type 2 diabetes (n=588). Icodec reduced HbA1c by 1·57% at week 26, versus 1·36% with degludec. Level 2 or 3 hypoglycaemic events were rare in both groups and differences in bodyweight increase across the two groups during the study period were not significant. Serious adverse events occurred in 15 (5%) of 294 participants in each group. The data show that once-weekly icodec is safe and superior to once-daily degludec in reducing HbA1c with a lower number of insulin injections, facilitating adherence and reducing the burden of treatment. Shortly after, Julio Rosenstock (Velocity Clinical Research at Medical City Dallas, USA) presented data from the ONWARDS 1 trial, the longest (52 weeks plus 26-week extension) substudy of the six randomised controlled trials in the ONWARDS programme. This 1:1 randomised, open-label, phase 3a trial assessed the long-term efficacy and safety of once-weekly insulin icodec versus insulin glargine U100 in individuals with type 2 diabetes inadequately controlled with non-insulin glucose-lowering agents (n=984). Prespecified primary analyses showed improved HbA1c reduction from baseline with icodec (8·5% to 6·9% vs 8·4% to 7·1% with glargine U100). No significant differences were noted in mean weekly insulin dose or in bodyweight change from baseline. Serious adverse events occurred in 64 (13%) of 492 individuals in the icodec group and in 71 (14%) of 492 individuals in the glargine U100 group. Level 2 or 3 hypoglycaemic events between baseline and week 52 were low in both groups, with non-significantly higher rates with icodec. More patients reached an HbA1c of less than 7% without level 2 or 3 hypoglycaemia with icodec than with glargine U100 (53% vs 43%; p=0·0028). Glycaemic control (HbA1c, time spent in target glycaemic range, and HbA1c <7% without hypoglycaemia) was also significantly improved by once-weekly icodec versus daily glargine U100, providing further data to support a transition to once-weekly insulin therapy in type 2 diabetes.